Allowance for Doubtful Accounts (Tables)

3 Months Ended

Mar. 31, 2020

Receivables [Abstract]

Summary of Allowance for Doubtful Accounts

The allowance for doubtful accounts consisted of the following (in millions):

	March 31,
	2020		2019
Balance at beginning of year	$	3.1	$	2.1
Provision charged to expense		0.1		—
Write-offs, less recoveries		—		(0.1	)
Balance at end of period	$	3.2	$	2.0